My favorite Martian landed in western NY recently and made conclusions based on correlations.

Which of the following correlation related events make sense? Tell why or why mot. Include information about sign and conclusion.

Example: The correlation coefficient between natural disaster and the number of doctors in the area was .95. The Martian concluded that doctors cause spontaneous generation natural disasters.

Answer: the correlation coefficeint is high, positive, and variable effects are likely casual. The number of doctors and the occurences of natural disasters do vary up and down together. But the Martian reversed the order of cause. It is the natural disaster that caused the doctors to arrive, not vice versa.

A. The correlation coefficient between drug use and school grades was - .95. The Martian concluded that poor grades drive students to take drugs.

B. The correlation coefficient between polar bear death and average artic summer temp readings is 85. The Martian cncluded that higher temps directly caused bear deaths.(hint: is there a third variable that might be at work here?)

C. The correlation coefficient between daytime mean temp and cash spent on pet rocks was .05. The Martian concluded that there was no effect between these variables.